用原位聚合法制备的PA6/GO纳米复合材料的结构和性能

以己内酰胺(CL)和6-氨基己酸(ACA)为聚合反应单体,用Hummers法制备氧化石墨烯(GO),再以GO为纳米填料用原位开环聚合法制备了GO改性PA6纳米复合材料(PA6/GO),并对PA6/GO纳米复合材料的结构及性能进行了研究。结果表明,PA6的黏均分子量达到104数量级,但加入过多的GO使PA6的分子量降低。形貌分析表明,GO均匀地分散在PA6基体中,并诱导了PA6基体的晶型由α晶型转变成γ晶型。同时,GO作为异相成核剂促进了PA6/GO复合材料中PA6基体的结晶,提高了PA6/GO复合材料的结晶度。拉伸测试结果表明,随着GO的加入PA6/GO纳米复合材料的拉伸强度先提高后降低,GO加入量为0.4份时拉伸强度达到最大值61.72 MPa,比纯PA6(48.52 MPa)提高了27.21%。导热性能分析表明含1.0份GO的PA6/GO纳米复合材料其50℃和100℃的热导率分别为0.317 W/(m·K)和0.280 W/(m·K),较纯PA6分别提高了33.19%和33.23%。

Structure and Properties of PA6/GO Nanocomposite by In-situ Polymerization

Graphene oxide (GO) modified polyamide 6 nanocomposites (PA6/GO) were prepared by in-situ ring-opening polymerization with caprolactam (CL) and 6-aminocaproic acid (ACA) were used as polymerization monomers and GO as nano-filler. The structure and morphology of PA6/GO nanocomposites were characterized. The results shows that GO was uniformly dispersed in the PA6 matrix. The viscosity average molecular mass of PA6 reached 10⁴ orders of magnitude, but the excessive addition of GO would decrease the molecular mass of synthesized PA6. The addition of GO induced the transformation of crystallographic structure of the PA6 matrix from α-type to γ-type. At the same time, as a heterogeneous nucleating agent, GO promotes the crystallization of PA6 matrix in PA6/GO composites, and increases the crystallinity of PA6/GO composites.. Tensile strength of PA6/GO composites increased first and then decreased with the addition of GO. When the amount of GO was 0.4% (in mass fraction), the tensile strength of PA6/GO nanocomposites reached a maximum of 61.72 MPa, which was superior to that of pure PA6 (48.52 MPa) by 27.21%. When the GO content was 1.0% the thermal conductivity of PA6/GO nanocomposites reached 0.317 W/(m·K) and 0.280 W/(m·K) at 50℃ and 100℃, which were 33.19% and 33.23% higher than that of pure PA6, respectively.